Locating ship strike risk hotspots for fin whale (Balaenoptera physalus) and sperm whale (Physeter macrocephalus) along main shipping lanes in the North-Western Mediterranean Sea

Abstract The Pelagos Sanctuary is the only pelagic marine protected area in the Mediterranean Sea, instituted for the conservation of cetaceans. Considering the number and size of commercial and touristic ports located along its coasts, this protected area is highly impacted by human activities, and especially marine traffic. Fin whales and sperm whales are regularly sighted in the Pelagos Sanctuary, and ship strikes with large vessels are one of the main threats affecting these two species. Mapping hotspots of distribution along main shipping lanes could be an effective conservation tool, as they directly allow locating high risk areas. In this work, we used data collected during summer from 2009 to 2019, along main marine traffic corridors in the central region of Pelagos Sanctuary. Ship strike hotspots have been identified, considering the persistence of distribution hotspots over the 11 years period. Hotspots occurrence has then been predicted over the entire Pelagos Sanctuary area applying Generalized Additive Models, allowing for ship strike risk assessment over the marine protected area. Our results highlighted the recurrence of important areas for both species along shipping lanes characterized by high vessel traffic, identifying regions where to address conservation measures

Acoustic recordings of rough-toothed dolphin (Steno bredanensis) offshore Eastern Sicily (Mediterranean Sea)

Author Posting. © Acoustical Society of America, 2019. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 146(3), (2019): EL286-EL292, doi:10.1121/1.5126118.ough-toothed dolphin's abundance and distribution is largely unknown worldwide and evaluation of its conservation status in the Mediterranean Sea is necessary. A rough-toothed dolphin was sighted offshore Eastern Sicily (Mediterranean Sea) in July 2017 and acoustic data were acquired in the same area of Watkins, Tyack, Moore, and Notarbartolo di Sciara [(1987). Mar. Mamm. Sci. 3, 78–82]. An automatic detection algorithm was developed to identify the echolocation clicks recorded within both datasets and a recurrent inter-click interval value was identified during the new encounter. Distinctive whistle classes were also identified with similar contour shapes within both datasets.The research has been partially funded by ONR Award (No. N00014-16-1-3017) and National Natural Science Foundation of China (Nos. 41422604 and 41306169). The authors declare that they have no conflict of interest. They wish to thank Professor Gianni Pavan for the software seapro. F.C. wants to thank the President's International Fellowship Initiative (PIFI) of the Chinese Academy of Sciences. F.C. and V.S. contributed equally to this work.2020-03-2

Biogeography in the deep : hierarchical population genomic structure of two beaked whale species

Funding for this research was provided by the Office of Naval Research, Award numbers N000141613017 and N000142112712. ABO was supported by a partial studentship from the University of St Andrews, School of Biology; OEG by the Marine Alliance for Science and Technology for Scotland (Scottish Funding Council grant HR09011); ELC by a Rutherford Discovery Fellowship from the Royal Society of New Zealand Te Aparangi; NAS by a Ramon y Cajal Fellowship from the Spanish Ministry of Innovation; MLM by the European Union’s Horizon 2020 Research and Innovation Programme (Marie Skłodowska-Curie grant 801199); CR by the Marine Institute (Cetaceans on the Frontier) and the Irish Research Council; and MTO by the Hartmann Foundation.The deep sea is the largest ecosystem on Earth, yet little is known about the processes driving patterns of genetic diversity in its inhabitants. Here, we investigated the macro- and microevolutionary processes shaping genomic population structure and diversity in two poorly understood, globally distributed, deep-sea predators: Cuvier’s beaked whale (Ziphius cavirostris) and Blainville’s beaked whale (Mesoplodon densirostris). We used double-digest restriction associated DNA (ddRAD) and whole mitochondrial genome (mitogenome) sequencing to characterise genetic patterns using phylogenetic trees, cluster analysis, isolation-by-distance, genetic diversity and differentiation statistics. Single nucleotide polymorphisms (SNPs; Blainville’s n = 43 samples, SNPs=13988; Cuvier’s n = 123, SNPs= 30479) and mitogenomes (Blainville’s n = 27; Cuvier’s n = 35) revealed substantial hierarchical structure at a global scale. Both species display significant genetic structure between the Atlantic, Indo-Pacific and in Cuvier’s, the Mediterranean Sea. Within major ocean basins, clear differentiation is found between genetic clusters on the east and west sides of the North Atlantic, and some distinct patterns of structure in the Indo-Pacific and Southern Hemisphere. We infer that macroevolutionary processes shaping patterns of genetic diversity include biogeographical barriers, highlighting the importance of such barriers even to highly mobile, deep-diving taxa. The barriers likely differ between the species due to their thermal tolerances and evolutionary histories. On a microevolutionary scale, it seems likely that the balance between resident populations displaying site fidelity, and transient individuals facilitating gene flow, shapes patterns of connectivity and genetic drift in beaked whales. Based on these results, we propose management units to facilitate improved conservation measures for these elusive species.Publisher PDFPeer reviewe

Cetacean in the Pelagos Sanctuary: Need for a multi-scale management approach

We use 5-years summer data (2009-2013 late May-end of September) systematically collected along fixed transects crossing the Pelagos Sanctuary (PS-Northwestern Mediterranean). We examine species habitat preferences at different spatial/temporal scales. Broader patterns are investigated separately in the western and eastern region of PS. To allow direct comparison, yearly/monthly indexes of species presence are computed as a proportion of the encounter rate of the species in a region and the overall ER for the species in the PS (indexregion_sp_y/m=ERregion_sp_y/m/ERPS_sp where ER=n sightings/hours on effort). Habitat variability is examined using maps of the phytoplankton bloom, obtained by 1-km maps of sea surface chlorophyll distribution. At a finer scale, a 5km grid is used to map yearly/monthly species aggregation areas within each region.Strong-interannual variability is shown, with the alternation of \u2018rich\u2019 (eg.2010-2012-2013) and \u2018poor\u2019 years (eg.2009-2011). Striped dolphin (sc) and fin whales (bp) in the eastern region well reflect this pattern, while they show stability and constant increase, respectively, in the western region. Monthly indexes show no pattern for sc while reflect migratory movements from/into PS of fin whales. Cuvier\u2019s beaked whale (zc) peaks of presence coincide with lowest presence of sperm whales (pc), both yearly and monthly, evidencing spatial and temporal habitat partitioning among the two species. Risso\u2019s dolphin show strong fluctuations in the eastern region and is more rare in the western, while pilot whales are almost stable in both regions over the years, showing strong monthly preferences. Bottlenose dolphins alternate rich to poor years in both regions, with a preference for the eastern region and early summer months. Aggregation hot-spots are species specific. Bp and pc hotspots vary both yearly both monthly, while zc hotspots are consistent among years. Based on these results we propose a multi-scale approach for themanagement of thePelagos Sanctuar

Fin whale seasonal trends in the Pelagos Sanctuary, Mediterranean Sea

Since 2009, a cetacean presence and distribution long-term monitoring study has been ongoing in the Pelagos Sanctuary, a pelagic marine protected area located in the northwestern Mediterranean Sea. One of the objectives of this study is to assess trends in cetacean presence and distribution to achieve good environmental status (GES) of pelagic marine waters. We assessed the density variability of the fin whale (Balaenoptera physalus) in the Pelagos Sanctuary. We used data collected during summer months (Jun–Sep) from 2009 to 2013, along 2 fixed transects crossing the Pelagos Sanctuary, using ferries as platforms of opportunity. We compared 2 un-corrected indexes: the linear encounter rate and density index, computed applying distance sampling methodology to select the most precise method. We also evaluated the effect of environmental covariates (e.g., platform height, Beaufort sea state, wind speed and direction, cloud cover and rain, longitude, latitude) on abundance and density estimation. Finally, we defined an unbiased index and used it to analyze the temporal and spatial variability of fin whale density in the Pelagos Sanctuary. Fin whale density along the 2 transects varied on a yearly basis, with a peak in 2012 and 2013. Variability also occurred on a monthly basis, with a peak during the first half of the season. A longitudinal and a depth gradient were also evident, confirming differences in species displacement in the area. These results are consistent with previous studies, and update current knowledge of species presence in the area. The protocol tested in this work can be easily applied to the other cetacean species inhabiting the Pelagos Sanctuary providing a novel and cost-effective method to assess long-term trends in cetacean distribution and detect incipient changes in species density. © 2015 The Authors. Journal of Wildlife Management published by The Wildlife Society

Long-term trend analysis of deep diving cetacean species occurring in the Pelagos Sanctuary (Northwestern Mediterranean Sea).

Several threats are known to affect cetacean species and their habitats in the Mediterranean sea, most of them being related to human activities. To enforce effective mitigation actions, extensive knowledge of cetacean ecology is required. In this study a 23-year sighting series (1990-2012) of sperm whale (Physeter macrocephalus), Risso’s dolphin (Grampus griseus) and Cuvier’s beaked whale (Ziphius cavirostris) was analysed to assess temporal patterns or trends in their presence in the Pelagos Sanctuary area. Sighting data were collected by Tethys Research Institute (n= 434) and CIMA research Foundation (n= 142) during shipboard surveys conducted between 1990-2012 and 2004-2012, respectively. This effort yielded a total of 576 sightings: 289 sperm whales, 164 Risso’s dolphins and 123 Cuvier’s beaked whales. For the purpose of the analysis a grid of 6.8 x 9.3 km cell units was created and used for the spatial analysis. The species’ encounter rate variability in time was analysed through a General Linear Model approach, which revealed the existence of a significant increasing trend (P<0.05) for sperm whales and Cuvier’s beaked whales presence in the area. Contrarily, no trend was found for Risso’s dolphin. This study provides evidence that the animal distribution in the Pelagos Sanctuary is affected by some drivers of change. Changes may be due to a wide range of causes (i.e. prey availabilities, climate change, noise). The correlation of the results obtained with this long term trend analysis with the available time series of environmental variables (i.e. Sea Surface Temperature from remote sensing) and anthropogenic pressure affecting the area (i.e. maritime traffic, fishing activities) will provide essential information to evaluate the implications of the different factors of variability and their possible interactions in order to support appropriate management and conservation strategies

Cytochrome P450 1A1 and 2B protein expression as biomarker for the first assessment of the ecotoxicological status of Cuvier's beaked (Ziphius cavirostris) in the NW Mediterranean sea

Cuvier's beaked whale is one of the least known cetaceans in the world. The Mediterranean subpopulation is now ranked as data deficient (DD) in the “Red List of Threatened Species” by IUCN because data on distribution, population structure and abundance in the Mediterranean basin are lacking except for very limited areas. The few studies carried out on threats posed to this species highlight that one of the main threat is the underwater noise but the ecotoxicological risk it is unknown. The xenobiotics compounds (OCs, PBDEs, etc.) in the environment can accumulate along marine food chains, having noxious effects on marine predators especially on long-living species. The objective of this study is to investigate for the first time the ecotoxicological status of Cuvier's beaked whale in the NW Mediterranean Sea (Pelagos Sanctuary). Among the diverse investigations that can be performed to obtain information about the health status of a species, a useful tool is represented by biomarkers. In this study the expression and induction of cytochrome's P450 (CYP1A1 and CYP2B isoforms) was evaluate as a molecular biomarker of exposure to OCs in 22 skin biopsies of free-ranging specimens belongings of both sexes and different age classes. This sample represent about the 20% of the resident population in the area which has been monitored during the last fifteen years. In the same samples the OCs levels (HCB, DDTs and PCBs) were analysed. This study represents an important step forward in our understanding of the effects of toxic compounds on Cuvier's beaked whale, considering also the information gathered on the gender differences, age and the life history of the animals. Further investigations need to be performed in this and other areas to better understand the ecotoxicological status of this data deficient species

Assessing the consistency of data collected using ferries as platforms of opportunity for cetacean monitoring programs

The aim of this work is to investigate the consistency of data collected using ferries as platform of opportunity, for estimating cetacean distribution and abundance in the Pelagos sanctuary. Distance sampling analysis is aimed to transform line transect data into densities calculated on a strip defined by Effective Strip Width (ESW). During summer 2011, 32 different Marine Mammal Observers (MMO) collected data onboard of 10 different ferries along 4 different routes crossing the Ligurian sea. Each ferry trip was considered as a strip-transect, surveyed once a week, all long the season. The study analyzes the influence of MMO and ferry characteristics (height of bridge and speed) as bias on data. To do so, ESW is estimated along each route as a measure of the effectively surveyed area. GLMs have been applied to verify the effects of the three studied variables (MMO, height of bridge and speed) on the perpendicular distances. Strong differences have been found among ESW along the four different routes with consequences on the estimated sampled strip (which ranged between 0.6 and 2.7 km2 width). Furthermore, we established that the ESW differences are mainly due to differences in species composition per route (e.g. average ESW for fin whales, bp, is 1640 m while average ESW for striped dolphins, sc, is 441 m). Thus, GLMs model have been fitted separately for striped dolphins and fin whales. For both species, the only studied parameter affecting sighting perpendicular distance is the bridge's height (P_value_sc=1.01E-07; P_value_bp= 8.05E-02), while ferry speed and MMO don't show any significative statistical influence. Regional differences and platform characteristics should then be taken into account when analyzing this kind of dataset for density estimation purposes. Nevertheless, data collected from ferries are a valuable source for monitoring programs on cetacean presence and distribution within wide areas